1. Field of the Invention
The present invention relates generally to a methodology of transient fuel control for an internal combustion engine in a motor vehicle and, more specifically, to a neural network based transient fuel control method for an internal combustion engine in a motor vehicle.
2. Description of the Related Art
A motor vehicle is typically powered by an internal combustion engine which generally operates in two modes, steady state and transient. A steady state mode could be characterized by maintaining the vehicle at a constant engine speed and load, whereby the power demands on the engine do not fluctuate. In contrast, a transient mode could be characterized by driving the vehicle under varying conditions, such as accelerating, decelerating, or climbing a grade, whereby the power demands are continuously changing.
Precise metering of the amount of fuel and air delivered to the engine is necessary to achieve the desired combustion as well as acceptable vehicle emissions. It is more difficult to maintain this mixture, known as the air/fuel ratio, when the vehicle is operating in a transient mode. For example, when the vehicle is accelerating, fuel demands increase to meet increased power needs. Conversely, when the vehicle is decelerating, fuel demands decrease to meet decreased power requirements. At steady state, fuel demands remain constant.
Traditionally, an engine controller receives inputs from a variety of sensors providing information regarding vehicle operating conditions such as engine speed, throttle position, and spark advance. The controller processes the information, determines the requisite amount of air and fuel, and relays this information to a fuel actuator (e.g., a fuel injector), which adjusts the fuel flow rate to provide the precise amount of fuel to the engine. One method of determining the amount of fuel is through the use of look-up tables within the controller containing information regarding the amount of fuel required during certain vehicle operating conditions, including transient and steady state modes. The information contained within the tables is experimentally derived from a combination of vehicle testing and engineering experience. This process can be time consuming and costly.